1. Field of the Invention:
The present invention relates generally to helicopters and/or other similar types of hovering aircraft, and more particularly to a parachute-type safety lowering or descent system for helicopters and/or other similar types of hovering aircraft whereby a disabled or inoperative airborne helicopter and/or similar type of hovering aircraft can nevertheless achieve a relatively soft landing as opposed to a crash landing which would obviously be detrimental to both the aircraft and its personnel aboard the aircraft.
2. Description of the Prior Art:
As is well known in the art, helicopters and similar types of hovering aircraft achieve and maintain their airborne mode as a result of the proper performance of the main overhead rotor or rotors, and as is additionally appreciated, such aircraft exhibit virtually no glide characteristics upon disablement of the rotor or rotors, whether such is due in fact to, for example, a rotor blade separation or fracture, in whole or in part, relative to the rotor blade hub, a failure in the main rotor drive engine, or the like. Consequently, upon disablement or inoperativeness of the main rotor or rotors, or the main rotor drive engine, and even under those conditions wherein the rotor or rotors are rotating freely in a non-powered mode whereby a slower rate of descent may be achieved than would be able to be achieved under the conditions wherein the rotor or rotors were not at all rotating, or had been separated from the aircraft, the aircraft would in all probability crash, or certainly land in a manner which would not be considered a relatively safe or acceptable soft-landing, with a consequent loss of both the aircraft and personnel. Due to the normal mode of operation of helicopters or similar type of hovering aircraft, it is further appreciated that such aircraft usually fly at relatively low altitudes. Consequently, should the aircraft experience rotor, rotor blade, or rotor drive engine failure, the aircraft would probably be at an altitude which would render it unsafe for personnel to jump from the aircraft to the ground without deploying their parachutes, whereas, on the other hand, the aircraft would similarly be at an altitude which is considered too low for the deployment of the personnel parachutes if in fact the airmen did jump from the aircraft toward the ground. As a result, as is often the unfortunate situation, should the rotor or rotor blades, or the rotor drive engine, experience a malfunction or failure, both the aircraft and its personnel are in fact lost or seriously damaged, or critically injured or killed, respectively. A need therefore exists for the provision of a safety lowering or descent system for helicopter or other type of hovering aircraft whereby such aircraft can in fact achieve a relatively soft and safe descent and landing under rotor, rotor blade, or rotor drive engine failure or malfunction conditions.
Such a helicopter or other type of hovering aircraft safety lowering or descent system is in fact shown, for example, to already exist within the U.S. Pat. No. 3,138,348 which issued to Stahmer in 1964, however, it is submitted that such a disclosed system has serious operational disadvantages or drawbacks which render the operativeness of such a system as being questionable. It is noted, for example, that a parachute descent system is provided for the helicopter aircraft wherein the descent or lowering parachute, for safely lowering the helicopter at a relatively safe descent rate of speed under the engine failure conditions, is housed within a housing 40 which is fixed atop the rotor hub 20 by means of a mounting plate 30. Consequently, as might be appreciated, it is submitted that a system such as that of Stahmer might be operationally defective under actual operational or deployment conditions in view of the fact that the mounting plate 30, housing 40, and the parachute 60 contained within housing 40, will all rotate along with the rotor hub 20. As a matter of fact, it is seen from FIG. 2 of Stahmer, for example, that the tie lines 110 of the parachute 60 are directly secured to rotor hub 20 by means of a ring 114 and an attachment member 120. Consequently, upon deployment of the safety parachute 60 from the housing 40 under engine failure conditions, it is highly likely that the tie lines 110 of the parachute will become twisted about or between themselves due to the continued rotation of the rotor hub 20 under partial power or inertial conditions. Such twisting or fouling of the parachute tie lines will in fact prevent full and proper deployment of the chute whereby the same will not in fact be able to properly and safely sustain or support the disabled aircraft with an inevitable loss or damage to the craft, as well as, of course, serious injury of death to its airborne personnel.
The aforenoted type of operational defect or drawback appears to have been resolved within a system such as that proposed in Koppen (German Offenlegungsschrift No. 2503461) which issued in 1976 wherein a dual-tier or dual-level ball bearing system is employed for rotationally separating the rotor blades and the rotor hub from the parachute housing. While it is noted that the precise purpose of such a ball-bearing system is in fact to prevent the parachute lines from becoming twisted as a result of either the rotation of the helicopter rotor or the helicopter per se, there is nevertheless an operational disadvantage, drawback, or defect present within even such a system such as that proposed by Koppen, although such was apparently not recognized by such inventor. Should a rotor or rotor drive engine failure occur and the parachute safety lowering or descent system be deployed, upon deployment of the safety lowering or descent-controlling parachute, severe impact or impulse forces attendant the sudden deployment of the parachute and the consequent support of the helicopter weight load will be immediately and instantaneously transferred to the rotor hub assembly through means of at least one of the sets of the dual-level ball bearings. Such forces or loads will tend to cause the ball bearings to at least momentarily freeze or jam, and possibly become irrevocably damaged, frozen, or jammed, and this may be particularly true of the ball bearing inner and/or outer race members. In light of these conditions, the parachute housing will no longer experience rotational separation, freedom, or independence from the rotor hub assembly, and consequently, the parachute housing, along with the parachute and the parachute tie lines, will tend to rotate along with the helicopter rotor blades, the rotor hub assembly, or the helicopter per se, thereby leading to twisting or fouling of the parachute tie lines. A similar system, with similarly potentially problematical operational disadvantages is likewise shown in U.S. Pat. No. 2,812,147 which issued to Trabucco in 1957.
A need therefore still remains to provide a helicopter or similar type hover-craft safety parachute lowering or descent system wherein the aircraft and its personnel can in fact be safely lowered to the ground under rotor, rotor blade, rotor hub, or rotor drive engine failure conditions.
A primary objective then of the present invention is to provide a new and improved helicopter or similar-type hover-craft parachute safety lowering or descent system.
Another objective of the present invention is to provide a new and improved helicopter or similar-type hover-craft parachute safety lowering or descent system which overcomes the various operational disadvantages, drawbacks, and defects of current or conventionally-known helicopter or similar-type hover-craft parachute safety lowering or descent systems.
Still another objective of the present invention is to provide a new and improved helicopter or similar-type hover-craft parachute safety lowering or descent system which can in fact safely lower a disabled helicopter and its personnel to the ground under, for example, rotor, rotor blade, rotor hub, or rotor drive engine failure conditions.
Yet another objective of the present invention is to provide a new and improved helicopter or similar-type hovercraft parachute safety lowering or descent system wherein under normal operating conditions of the helicopter or similar-type aircraft, the parachute safety lowering or descent system of the present invention may be stowed so as not to interfere with such normal operation of the aircraft and yet may be deployed under emergency, disablement conditions of the aircraft.
Still yet another objective of the present invention is provide a new and improved helicopter or similar-type hover-craft parachute safety lowering or descent system wherein when the parachute is disposed within its stowed position, the same is contained within an aerodynamically streamlined housing disposed atop the rotor hub assembly so as to not to interfere with the normal airborne performance characteristics of the aircraft.
Yet still another objective of the present invention is to provide a new and improved helicopter or similar-type hover-craft parachute safety lowering or descent system wherein when the parachute is deployed for its safety lowering or descent function, twisting, tangling, or fouling of the parachute tie or shroud lines will be prevented so as to insure full and complete or proper deployment of the chute system whereby in fact the disabled aircraft can be safely lowered to the ground at a proper or acceptable rate of descent in order to achieve a relatively soft and safe landing for preserving intact the aircraft per se as well as minimizing any injuries to on-board personnel.
A further objective of the present invention is to provide a new and improved helicopter or similar-type hover-craft parachute safety lowering or descent system wherein not only is there employed a dual set of ball bearings for initially rotatably isolating the parachute housing from the rotor hub assembly whereby induced rotational effects of the rotor are not impressed upon the parachute housing and the parachute contained therein so as not to twist, tangle, or foul the parachute tie or shroud lines, but in addition, means are mounted upon the exterior of the parachute housing so as to be movable from a stowed position to a deployed position so as to prevent any induced rotation from being transferred from the rotor hub assembly to the parachute housing under such load conditions wherein the ball bearings, and/or their inner and outer race members, may become jammed, frozen, or otherwise damaged, whereby in fact the parachute safety lowering or descent system of the present invention may be deployed for its safety lowering operation or descent function while preventing any entanglement, twisting, or other fouling of the parachute tie or shroud lines such that the parachute can be fully and properly deployed so as to be capable of achieving its controlled, safe lowering or descent of the disabled aircraft.